In this study, methylene blue adsorption was investigated using different agricultural waste shells (chestnut shell, hazelnut shell, walnut shell). XRD (X-Ray Diffraction), SEM (Scanning Electron Microscopy), FTIR (Fourier Transform Infrared Spectroscopy) analyzes were performed for the characterization of shells. The effects of mixing time, initial methylene blue concentration, temperature and adsorbent amounts were determined for methylene blue adsorption. Equilibrium isotherms for adsorption of methylene blue by chestnut, hazelnut and walnut shell were experimentally measured. The obtained data were analyzed using linear and nonlinear correlations for different temperatures using the Langmuir, Freundlich, Dubinin-Radushkevich, Frumkin, Temkin, Elovich, Hill, isotherms. The best results on methylene blue adsorption on these adsorbents were obtained in chestnut shell.